This training program, currently in its 14th year, trains researchers to conduct interdisciplinary research at the intersection of Psychology and Medicine to develop better understanding and treatment of mental and physical diseases. Our fellows learn to conduct translational research, applying psychological theories and research on health behaviors and on stress and psychobiology to the prevention and amelioration of diseases including Major Depression, PTSD, and AIDS. Fellows focus in one of these two emphasis areas, but share a common didactic core which includes two seminars, the Psychology and Medicine seminar, and the Research Process Seminar, and a course in the Responsible Conduct of Research. Cross-cutting both areas is an emphasis on social context and health disparities, methods for causal modeling, and intervention research. The program benefits from its placement on a leading health sciences campus, with strong training and research programs in the biological, social/behavioral, and clinical sciences. We have a track record of training outstanding researchers who have gone on to productive research careers. Changes since the last application and/or proposed for the next period include: (I) increased focus on mental illness, (2) greater psychobiological focus, (3) increased emphasis on social context, (4) new core and affiliated faculty in these areas (4) establishment of an Executive Oversight Committee, and (6) coordination with the Psychiatry residency program to recruit MD-fellows. The program now has 25 core and 35 affiliated faculty, and a 6- member Executive Committee whose members span basic and applied research, Psychology and Psychiatry, and behavior and stress/psychobiology. Our faculty are distinguished by a high degree of research activity and collaboration both among the training faculty and with faculty from other fields. During two years of post-doctoral training, fellows will take the required seminars and supplementary courses where needed, undertake independent research with supervision of a primary mentor and submit at least one significant paper from that research, complete a draft of a grant application, submit additional papers from their dissertation and secondary projects with program faculty, and present at a minimum of two national conferences. Past fellows have been very productive and successful, with the majority of them conducting highly regarded interdisciplinary research at the interface of the behavioral sciences and medicine in medical or academic centers. We request funding for four new fellows a year. This represents an increase of one fellow to allow us to recruit a psychiatrist to be identified during their residency.